Distillate petroleum hydrocarbon fuel compositions containing novel multifunctional additives

ABSTRACT

DISTILLATE PETROLEUM HYDROCARBON FUEL COMPOSITIONS SUCH AS GASOLINES, JET FUELS OR DIESEL FUELS ARE COMPOUNDED TO CNTAIN SMALL AMOUNTS OF AT LEAST ONE AMIDE FORMED BY CONDENSING A BASIC SIX-MEMBERED HETEROCYCLIC ORGANIC COMPOUND CONTAINING ONLY CARBON ATOMS AND NOT MORE THAN TWO NITROGEN ATOMS IN THE RING AND WHEREIN THE COMPOUND CONTAINS AT LEAST ONE NITROGEN ATOM CONTAINING AT LEAST ONE HYDROGEN ATOM ATTACHED THERETO, WITH AN ACIDIC COMPOUND WHICH MAY BE AN ALIPHATIC MONO OR DICARBOXYLIC ACID, ITS ANHYDRIDE OR THE CORRESPONDING ACID HALIDES OR DERIVATIVES THEREOF CONTAINING FROM 6 TO 20 CARBON ATOMS PER MOLECULE. BETWEEN ABOUT 5 AND 150 POUNDS OF ADDITIVE IS USED PER 1000 BARRELS OF DISTILLATE FUEL. GENERALLY BETWEEN ABOUT 0.001 AND ABOUT 1 WT. PERCENT OF THE ADMIXTURE IS USED. SUCH ADDITIVES IMPART CLEANLINESS, RUST INHIBITING AND DETERGENCY PROPERTIES TO THE FUELS.

United States Patent DISTILLATE PETROLEUM HYDROCARBON FUEL COMPOSITIONS CONTAINING NOVEL MULTI- FUNCTIONAL ADDITIVES Norman Jacobson and Jack Ryer, East Brunswick, N.J., assiguors to Esso Research and Engineering Company No Drawing. Continuation of abandoned application Ser. No. 739,178, June 24, 1968. This application Oct. 29, 1971, Ser. No. 193,693

Int. Cl. C101 1/22 US. Cl. 44-63 2 Claims ABSTRACT OF THE DISCLOSURE Distillate petroleum hydrocarbon fuel compositions such as gasolines, jet fuels or diesel fuels are compounded to contain small amounts of at least one amide formed by condensing a basic six-membered heterocyclic organic compound containing only carbon atoms and not more than two nitrogen atoms in the ring and wherein the compound contains at least one nitrogen atom containing at least one hydrogen atom attached thereto, with an acidic compound which may be an aliphatic mono or dicarboxylic acid, its anhydride or the corresponding acid halides or derivatives thereof containing from 6 to 20 carbon atoms per molecule. Between about and 150 pounds of additive is used per 1000 barrels of distillate fuel. Generally between about 0.001 and about 1 wt. percent of the admixture is used. Such additives impart cleanliness, rust inhibiting and detergency properties to the fuels.

This is a continuation of application Ser. No. 739,178, filed June 24, 1968 now abandoned.

DESCRIPTION OF THE INVENTION Present-day gasolines, jet fuels and diesel fuels are employed in engines which have air pollution control devices, such that more stringent requirements are imposed on these engines. These engines utilize such fuels because for the most part the fuels have been tailored to make the best use of the octane properties, volatility, etc., although in all respects they do not constitute entirely troublefree admixtures. Combustion of the fuel is often not complete in such internal combustion engines. Studies have shown that some of the unburned hydrocarbons undergo complex polymerization and oxidative reactions by reason of their uncombusted or their partially combusted condition. Also, carbonaceous and other insoluble materials are found to have been formed not only on the combustion valves but in the throats and venturies of the carburetor and on the injection valves of the diesel engines. Somes of these degradation particles also find their way into the crankcase and are admixed with the lubricating oils and thereby contribute to the excessive formation of lubricating oil sludge and varnish. The role which such combustion chamber deposits play in promoting surface ignition, spark plug fouling, rumble, increase in octane requirements and similar related combustion difiiculties is generally well known. Deposits tend to be formed and accumulate in the fuel injection valves and in the intricate and essential parts of the carburetor thus causing malfunction of these fuel combustion preparatory devices and this necessitates frequent shutdown for cleaning and other repairs of these mechanical parts.

In the past, various dispersant and detergent-type additives have been employed, of an ashless type, for addition to mineral lubricating oils for the purpose of suspending sludge and varnish forming particles and to effect general cleanliness in those engine areas Where the lubricating oil comes in contact with the areas. For the most part, the idea of employing detergent-type additives for fuel compositions has been generally avoided for the reason that 3,728,091 Patented Apr. 17, 1973 difliculties are encountered if the additives are of a nonvolatile nature and for the reason that the degradation or oxidized degradation products of such additives oftentimes are corrosive in nature and tend to adversely attack the various internal surfaces of fuel injection valves and carburetors. The problem of fouling of the internal surfaces of engines both in the passageways leading to the explosion chambers and in the areas being contacted with the lubricating oil compositions is accentuated because of the blow-by of combustion gases and unburned fuel from the combustion chamber of the engine so that not only are the deposits in both areas of whatever nature to be reckoned with but in addition the deposits or corrosion products resulting from the blow-by directed by the positive ventilation control valve and combusted gases are to be reckoned with as well. With the formation of deposits in a fuel i njection valve or in a carburetor, the engine, in each case, will idle in a rough manner and in some cases will stall. The trouble is still further aggravated in present-day engines because it is not desirable to exhaust to the atmosphere the exhaust gases. Since many of these gases are retained in the combustion chamber and in the crankcase areas by reason of the presentday usage of positive crankcase ventilating valves, a back mixing of fumes in the venturies of carburetor and injection valves takes place thus causing an increased tendency for deposits to form in these areas. Itis thus readily apparent that any material that can be added to distillate fuels that will impart carburetor or injection valve detergency and cleanliness while at the same time exhibiting antirusting tendencies will be of considerable benefit in the operation of gasolines, jet turbines, or diesel engines. This general imparting of engine cleanliness, non-rusting and non-corrosive tendencies is distinctly advantageous.

The present invention is directed to the use of certain types of distillate fuel soluble heterocyclic amides which unexpectedly have been found to have both a rust inhibiting quality and an engine cleanliness and an engine detergency quality for carburetor and fuel injection valves. These materials are prepared by condensing a basic sixmembered heterocyclic organic compound whose nucleus contains only carbon atoms and nitrogen atoms, the latter being present in no greater number than two and in which the compound also contains at least one hydrogen atom, and at most two hydrogen atoms, per nitrogen atom per molecule, with an acidic organic compound which is a C -C aliphatic mono or dicarboxylic acid, its anhydride or the corresponding acid halide derivative thereof. These amides which are soluble in the distillate fuels to the required extent at least, possess important detergency properties as well as important antirust properties and so far as has been determined do not impart to the fuels to which they are added undesirable properties such as loss in octane number, alteration in volatility characteristics, increase in stalling tendencies and the like.

A number of basic six-membered heterocyclic nitrogen containing organic compounds may be employed so long as at least one nitrogen atom in the molecule is of a primary or secondary nature, i.e., is capable of condensing with an acidic group. Typical compounds that may be employed may be of the saturated or unsaturated type. For example, the following may be used: S-aminomethyl pyridine (3-picolylamine), 3-aminomethyl pyrazine, 3- aminoethyl-Zethyl-pyridine (alpha butidine), 4-aminoethyl-3-propyl pyridine (beta conyrine), 3-aminomethyl parvoline. Additionally, the saturated heterocyclic compounds may be used, for example, 3-aminomethyl piperazine or 3-aminomethyl piperidine. Additionaily, N-(2- aminoethyl)piperazine, N-(Z-aminoisopropyl) piperazine, and N-N'-di(2-aminoethyl)piperazine may be employed. Similarly, the aminoalkyl nuclear C substituted pipera zines may be employed such as the Z-aminoalkyl, C substituted C -C alkyl piperazines. The aminoalkyl substituted derivatives of beta lupetidine, alpha lupetidine, beta pipecoline, copellidine and conine derivatives may be employed. These are compounds containing one or more C substituted short chain alkyl groups attached to the piperazine nucleus. Additionally, if a piperazine or a piperidine compound is employed, it is not necessary that there be attached to the ring structure an aminoalkyl group for the reason that both compounds already contain at least one secondary nitrogen atom and so are capable of reacting with acidic groups such as carboxylic acids, their anhydrides or the corresponding acyl halide compounds.

Various carboxylic acids, their anhydrides or their corresponding acid halide derivatives may be employed. Generally, the acidic materials will have from 6 to 20 carbon atoms per molecule and are aliphatic in nature. The following carboxylic acids may be used as such or they may be used in the form of their anhydrides or acid halide derivatives. Only the carboxylic acids are, however, specifically set forth. These acids are: suberic, pimelic, azelaic, sebacic, caproic, caprylic, capric, pelargonic, lauric, myristic, palmitic, stearic, palmitoleic, oleic, linoleic, linolenic, and ricinoleic. The acid halide derivatives are generally the acid chlorides or acid bromides since these are most readily available for use.

The condensation reaction between the acidic compound and the basic heterocyclic nitrogen compound is essentially a condensation reaction involving the formation of mono or dicarboxylic amides and is generally carried out at temperatures ranging between about and about 130 C., preferably between about 40 and about 120 C., for periods of time ranging between about 0.5 and about hours, preferably between about 1 and about 3 hours. Ordinarily, the reaction is carried out in the presence of an inert organic solvent such as, for example, an aromatic hydrocarbon, for example, benzene or toluene or in the presence of an aliphatic hydrocarbon, such as, for example, a heptane or octane, or, more conveniently, a mixture of hydrocarbons such as that which would ordinarily be used as a distillate fuel, i.e., a gasoline or jet fuel fraction. In many cases, the final product need not be isolated but the final mixture of solvent and reactant mixture should be treated to remove amine hydrochloride or hydrochloric acid if these are present and then it may be supplied as a concentrate which can be directly added to the same type of fuel as the solvent or even to a different type of fuel.

The fuel compositions to which the carburetor detergents and rust inhibitors are added are distillate petroleum hydrocarbon fuels such as motor gasoline, aviation gasoline, jet fuels, diesel fuels, kerosene, No. 2 heating oil and the like. In general, the boiling ranges for these various types of fuels are as follows:

Boiling range, F.

Such fuels are generally composed of mixtures of various types of hydrocarbons depending upon the particular use to which the fuel is to be put. Principally, these hydrocarbons are normal paraffins, isoparaflins, naphthenes, olefins and aromatics. A particular type of fuel and another type of fuel will vary as to the relative amounts or ratios of one type of constituent to another type of constituent present over considerable ranges not only because 9f the type of crude oil from which the particular fuel was derived but also because of the blending operations occurring within any particular refinery as well as the particular type of refinery operations and treatments to which fractions of the crude oil are subjected within the refinery. Thus for example, hydrocracking, catalytic cracking, al-kylation, hydroalkylation, hydroforming and various other types of unitary processes performed within a refinery are conventionally employed to produce products which may be blended or, as produced, are known to achieve certain desired final burning and physical characteristics for the particular fuels. Regardless of the specific chemical compositions of any particular fuels by reason of their methods of manufacture or by reason of the particular crude oils from which they are derived, the amide condensation products employed as additives according to the present invention do, in fact, impart carburetor and fuel injection valve detergency, cleanliness and rust inhibiting properties to such fuels.

Other conventional additives may also be employed in conjunction with the use of the aforementioned amides. For example, aviation fuel and motor gasoline fuels commonly will contain from 0.5 to 7.0 cc. per gallon of conventional antiknock agents such as tetraethyl lead, tetramethyl lead, dimethyl diethyl lead, or similar alkyl lead anti-knock compounds or mixtures thereof. Other conventional additives used are corrosion inhibitors, such as polymerized linoleic acid, N,C-dialkyl imidazolines; cold flow improvers, such as ethylene-vinyl acetate copolyrners; antioxidants, such as phenols and amino phenols; antifoulants such as tricresyl phosphate; combustion r'nodifiers, such as alkyl boronic acids, alkyl phosphates, and alkyl phosphites, octane appreciators, such as tertiary butyl acetate, lead scavengers, such as ethylene dichloride or dibromide, tribeta-chloroethyl phosphate and auxiliary anti-icing agents, such as isopropanol, hexylene glycol or the lower molecular weight dialkyl sulfoxides disclosed in British Pat. No. 807,010 and U.S. Pat. No. 2,932,560. Oil soluble dispersants and/or detergents having overall engine cleanliness, such as those disclosed in US. Pat. No. 3,223,495 may also be employed either in the; fuels or in the lubricating oils, or both, employed in association with the use of such fuels.

It is sometimes advantageous to employ solvent oil, i.e., a mutual solvent, for the distillate fuel and the amide additives in order to effectively introduce sufficient amounts of the additives into the fuel and to insure thorough distribution of the additives in the fuel. Such solvent oils generally have boiling ranges within the limits of 350 and 800 F. at 10 mm. mercury pressure, preferably a boiling range of 440 -700 F. under the same pressure. These oils generally have a viscosity within the range of 45 to 150 SUS at 210 F. Although the invention does not depend upon the use of either organic solvents for reaction nor upon the use of solvent oil or organic solvents for dispersing the amide into the distillate fuel, it is generally expedient to employ such solvents, at least to a limited extent, in order to insure complete solubility of the particular amide or mixture of amide being added tothe fuel. Heavier aromatic naphthas, mixtures of ethyl or propyl alcohol and xylene, benzene, toluene, polyhydric alcohols such as ethylene glycol or propylene glycol, ketones such as acetone and methylethylketone and ethers such as diethyl ether, di-isopropyl ether or the ethyl ethers of ethylene or propylene glycol are suitable solvents for insuring the effective and uniform distribution of the amide additives into the distillate fuels.

The following examples are given by way of illustration. It is not, however, intended that the invention be limited thereto.

Example 1 Twenty-five grams (.13 mole) of n-decanoyl chloride in 400 grams of toluene (C H COCI) were added dropwise, with stirring to 14.2 grams (.14 mole) of n-methyl piperazine likewise in 400 grams of toluene over a period of one hour and the reaction mixture was heated up to a temperature of C. with reflux. The reaction mixture was maintained at this temperature for about 0.5

hour. The product was washed twice with 500 cc. of a aqueous NaHCO solution and twice with 500 cc. portions of water. It was dried over anhydrous sodium sulfate and filtered. The toluene was removed from the filtrate with a rotary evaporator at 80 C. and 20 mm. pressure. The residue was distilled and 26.25 grams of n-methyl N-decanoyl iperazine having a boiling point of 176 C. at 3 mm. of mercury pressure were recovered.

Example 2 Sixty grams (.32 mole) of the same acyl chloride as employed in Example 1 in 400 grams of toluene was reacted with 13.6 grams (.16 mole) of piperazine in a reaction medium of 43.8 grams of triethyl amine and 200 grams of toluene at a temperature of 110 C. for about 30 minutes; then the reaction mixture was allowed to stir for an additional hour at 80 C. The product work up was similar to that as described in Example 1. The product was obtained after the removal of the toluene by the same method as described in Example 1. Forty-three grams of the N-N-didecanoyl piperazine having a melting point of 54 C., was recovered, having a purity greater than 90%.

Example 3 93.9 grams (0.49 mole) of the same acyl chloride as employed in Example 1 in 320 grams of n-heptane was reacted with 54.3 grams (0.50 mole) of amino beta picoline having the formula:

CHzNHI The reaction was carried out in the presence of 50.8 grams of triethyl amine and 400 grams of n-heptane, at a temperature of 50 C. and for a period of about 2.5 hours after which the product was washed twice with 500 cc. portions of 5% aqueous sodium bicarbonate and twice with 500 cc. portions of water. The organic layer contained precipitate which was filtered. The solid was recrystallized from boiling heptane, filtered, and dried. About 65 grams of the amine product was recovered. It had the formula:

D-CQHIBC ONHCH! -Pic0ly1)decanamide) and had a melting point of 79 C. and a purity greater than 90%.

Example 4 Carburetor detergency tests were then carried out to determine the etficiency of the amides prepared as described in the preceding examples. A base gasoline was prepared having the following inspection.

Conventional antioxidant-Concentration 2' lbs. per 1000 barrels (2.6 di-t-butyl phenol).

An automotive engine, 1964 Buick V-8 Special, 300 cu. inch, 11:1 compression ratio aluminum alloy engine equipped with a double barrel carburetor was run for 20 hours as a dirty up operation using Howell reference fuel and having the properties of excessive deposition of carbonaceous deposits in carburetor barrels. At the end of the dirty up period a fuel was used having the aboveshown inspection. In separate tests, the additives of Examples 2 and 3, respectively, in a concentration of 25 pounds of active ingredient per 1000 barrels (42 US. gallons) of motor fuel were incorporated into the above-identified fuel, the tests being run for an additional 20 hours. At the end of this test run, the sleeves and throttle plates of both barrels of the carburetor were removed, weighed and compared to the weight at the end of the first period, i.e., the dirty up period of the operation. The results obtained are given in Table I.

TABLE I Dirty-up Second period, period, Percent weight weight clean First period increase decrease up I Additive:

Sleeve No. 1 0148 (.0051) (34. 5) None Throttle plate N o 0023 0030) (13.0) Sleeve No. 2. 0129 0042) (32. 6) Throttle plate N 0027 0007) (25. 9) Sleeve No. 1 0110 0076 69. 1 Ex n Throttle plate No. 1 0023 0015 65. 2 Sleeve No. 2 0092 0049 53. 2 Throttle plate N o 2. 0021 0014 66. 6 le N 01:2 007g 53. 6 00 001 4 1 Sleeve N0. 2 014s 0036 24. 7 Throttle plate No. 2 0033 0003 9.1

1 Additional deposits are shown in parenthesis.

It is apparent from the foregoing data, as shown in Table I, that a drastic reduction in carburetor deposition was accomplished by reason of the use of the amide additives. The use of each of the amide additives reduced the carburetor deposits by an overall average of 63.5% in one case and by 33.6% in the other case.

Example 5 Using the same base fuel, a further series of tests were carried out to measure the amount of rusting which took place with and without the amide additives. The method was a modification of ASTM D-665. 350 cc. of the gasoline base blend, above described, with and without the amide additives, was held at a temperature of 77 F. and stirred with a polished soft steel spindle. After 10 minutes of stirring for the purpose of conditioning the spindle, a 50 cc. aliquot of the gasoline base blend together with 30 cc. of water was admixed. The stirring with the polished steel spindle Was continued for 1 hour while maintaining a 77 F. temperature. The steel spindle was then removed from the mixture of gasoline and water and inspected for rust spots. Rust that does not exceed 50% of the area of the spindle is considered as a satisfactory showing of lack of formation of rust. In all instances where the novel amide additives were employed, they were added in a concentration of 10 pounds of active ingredient per 1000 barrels of fuel. The results are given in Table II.

TABLE II Percent Additive Rating 1 rust None 5.8 90. Example 11 3.5 3. Example III 2.0 1 speck.

A 1.0 rating is clean, i.e., free of rust.

7 8 2. A gasoline according to claim 1 wherein said diamide 2,956,020 10/ 1960 Suprin et a1 44-66 X is N,=N'-didecanoyl piperazine. 3,444,170 5/1969 Norman et a1 4463 X 3,468,639 9/1969 Lindstrom et a1. 4466 References Cited 2,684,292 7/1954 Caron et a1 44-63 X SMITH, Aswan Exammer 2,844,446 7/1958 Cyba et a1 4463 

